K. Amemiya et al., Oxygen K-edge x-ray-absorption fine-structure study of surface methoxy species on Cu(111) and Ni(111), PHYS REV B, 59(3), 1999, pp. 2307-2312
The atomic and electronic structures of the methoxy (CH3O) adsorbate formed
on the Cu(111) and Ni(111) surfaces have been studied by NEXAFS (near-edge
x-ray-absorption fine structure) and SEXAFS (surface extended x-ray-absorp
tion fine structure) with a newly constructed soft x-ray beamline in the Ph
oton Factory. The transition from the O 1s core to the 2e level of the meth
oxy species was found to be noticeably stronger on Ni(111)than on Cu(111),
indicating that the methoxy adsorbate on Cu(111) is more anionic. The C-O b
ond lengths of the species on Cu(111) and Ni(111) were estimated using the
sigma*(C-O) resonance to be 1.46 +/-0.05 and 1.43+/-0.05 Angstrom, respecti
vely. The polarization-dependent NEXAFS measurements showed that the C-O ax
is of the methoxy adsorbate is nearly perpendicular to the surface on both
Cu(111) and Ni(111). From the SEXAFS analysis on Cu(111), it was revealed t
hat the oxygen atom of the methoxy species locates on a threefold hollow si
te and the nearest-neighbor O-Cu distance was determined to be 2.00+/-0.03
Angstrom. [S0163-1829(99)04903-6].